This invention relates to patch panels for interconnecting communication cables.
Telephone and data cables in a building, for example, interconnect telephone handsets and computer terminals located at desks and offices throughout the building with each other and with centralized communication facilities, including trunk lines, network servers, and PBX equipment.
To permit flexibility in configuring and later changing the interconnections, cables are run from each telephone, computer, trunk line, PBX, server, and other device, to a central interconnection "closet". The end of each wire of a cable is connected to terminals in a punch-down block which is part of a patch panel. The terminals of the punch-down block are in turn tied to accessible modular connectors. The final interconnection of cables is then achieved by short cables run between selected pairs of the connectors. To reconfigure the interconnection scheme, the user simply disconnects and reconnects the short cables to other pairs of the connectors.
Setting up an interconnection closet is a labor intensive activity. Typically, there are a large number of patch panels. Each patch panel must be assembled from supplies of metal plates and electrical pieces using large numbers of screws. The many hundreds of wires in the cables routed to the closet must be individually punched down into the blocks. Then the patch panels must be individually mounted on a rack or in a cabinet again often using screws.
Occasionally a new cable is run into the closet and must be punched down to one of the blocks. This requires the patch panel to be pulled down from its mounted location to permit access to the back of the blocks where the punching down is done; then the panel must be remounted.
Some patch panels have fronts which are hinged to swing left to right (this requires careful cable management to prevent excessive stresses on the wires) or top to bottom to give access to the back of the panel.
In any case, punching down typically requires that the patch panel be removed from the rack or wall to another location (e.g., a table) which is able to support the panel against the forces involved in the punch down process.
The cables which are punched down in the patch panel may have a variety of functions (e.g., high-speed data line, low-speed data line, voice grade line), and a variety of positions in the hierarchy of interconnect wiring distribution.
Patch panels typically include pre-printed numbers on the front panel which enable the user to identify the cables connected to it. Colors have also been used to indicate applications of the cables connected to the panel.